Registration and fusion of CT and MRI of the temporal bone

OBJECTIVE: To present and evaluate a registration method to fuse complementary information of CT and MRI of the temporal bone. METHODS: CT and MRI of the temporal bone of 26 patients were independently registered 4 times. A manual, iterative, intrinsic, rigid, and retrospective registration method was used. Mean CREm (consistency registration error) was calculated as a reproducibility measurement. RESULTS: CREm was 0.6 mm (95% CI = 0.52-0.68 mm). T-test revealed no difference between pathologic and normal cases (t[102] = -1.71; P = 0.09). Time needed: 13 minutes. In the registered and fused datasets, important bony surgical landmarks (eg, facial nerve canal, inner ear) could be assessed in 3 dimensions relatively to tumor tissue (eg, acoustic schwannoma). Fluid distribution within partially obliterated cochleae could be assigned to either scalae. CONCLUSION: An accurate, reproducible registration and fusion method that improves tumor surgery and cochlea implantation planning with only minor changes to the clinical workflow was presented and described. We suggest this method in selected cases.     

Lineage relationship between LNCaP and LNCaP-derived prostate cancer cell lines

BACKGROUND: LNCaP and its derivative cell lines, which include C4-2 (and the related C4-2B) and CL1, are used as models of prostate cancer. Unlike LNCaP, the other cell lines show features of progressed disease such as metastatic capability and hormone independence. Analyses were done to determine if C4-2 or CL1 cells were selected from pre-existent subpopulations in LNCaP. METHODS: Prostate cancer cells were characterized by cluster designation (CD) phenotyping. Specific cell populations were sorted by flow cytometry. DNA array analysis was used to probe differential gene expression. RESULTS: CD phenotyping showed that CL1 and C4-2 (and C4-2B) were very dissimilar, and C4-2 was more similar to LNCaP. One common difference between LNCaP and its derivatives was CD26, in which virtually all C4-2 or CL1 cells were CD26(+) but only approximately 10% of LNCaP cells were CD26(+). The CD26(+) subpopulation of LNCaP was isolated and cultured in vitro. After culture, a high percentage of the cells (descended from the sorted cells) were CD26(+), in contrast to those sorted by CD13 or CD44. The cultured CD13 and CD44 populations did not show a high percentage of CD13(+) and CD44(+) cells, respectively. CD13 and CD44 are markers, in addition to CD26, for CL1 but not for C4-2. CONCLUSIONS: C4-2 arose probably from CD26(+) LNCaP cells, while CL1 arose de novo.     

Outcome of Pregnancies after Biliopancreatic Diversion

Background: Severe obesity has deleterious effects on fertility and pregnancy outcomes. Although surgery is the best long-term treatment for severe obesity, there is a risk of gestational undernutrition in operated mothers because bariatric surgery reduces nutrient availability. This is a follow-up report of our initial findings regarding pregnancy and neonatal outcomes in biliopancreatic diversion (BPD) patients, with addition of a new cohort of children born to mothers after BPD. Methods: All women (n = 916) who had successfully undergone BPD in our hospital were mailed a questionnaire containing multiple-choice and essay questions concerning gynecologic and obstetric history, and pregnancy and neonatal outcomes in both preoperative and postoperative pregnancies. Patients operated between 1984 and 1995 (n = 568) were mailed an additional questionnaire regarding children's weight and height progress, and school performance. Perinatal records from our patients' obstetric clinics were also reviewed. Results: The questionnaire was completed by 783 women (85.5%). 251 postoperative pregnancies in 132 women resulted in 166 infants by 109 mothers. 47.0% of patients who were unable to become pregnant preoperatively were successful postoperatively. 90 out of 109 women (82.6%) reported an appropriate weight gain (9.1 ± 5.9 kg) during postoperative pregnancies. The incidence of fetal macrosomia decreased from 34.8 to 7.7%, with a concomitant increase in normalweight babies from 62.1 to 82.7%. The elevated miscarriage rate (26.0%) in these obese women persisted after surgery. Conclusion: Major weight loss following BPD improves the reproductive function of severely obese women. BPD provides major beneficial effects for both mother and child, including normalization of gestational weight changes, reduction of fetal macrosomia, and normalization of the infant's birth-weight. Our results speak in favor of delaying pregnancy in obese women until after the substantial surgical weight loss has occurred.     

Combined effects of energy density and portion size on energy intake in women

BACKGROUND: Increases in both the portion size and energy density of food have both been shown to increase energy intake, but the combined effects of such increases have not been investigated. OBJECTIVE: The objective was to determine the combined effects of energy density and portion size on energy intake in women. DESIGN: This study used a within-subjects design. Once a week for 6 wk, 39 women were served breakfast, lunch, and dinner ad libitum. The main entrée at lunch was formulated in 2 versions that varied in energy density (5.23 or 7.32 kJ/g), each of which was served in 3 different portion sizes (500, 700, or 900 g). The 2 versions were matched for macronutrient composition and palatability. Breakfast and dinner were standard meals. RESULTS: Increases in portion size and energy density led to independent and additive increases in energy intake (P <0.0001). Subjects consumed 56% more energy (925 kJ) when served the largest portion of the higher energy-dense entrée than when served the smallest portion of the lower energy-dense entrée. Subjects did not compensate for the additional intake by eating less at the subsequent meal. Despite substantial differences in energy intake, no systematic differences in ratings of hunger and fullness across conditions were observed. CONCLUSIONS: The energy density and the portion size of a food act independently to affect energy intake. The findings indicate that large portions of foods with a high energy density may facilitate the overconsumption of energy.     

The stereospecificity of flobufen metabolism in isolated guinea pig hepatocytes

Background

Extracellular nucleotides play an important role in the regulation of vascular tone and may be involved in cerebral vasospasm after subarachnoidal haemorrhage. This study was designed to characterise the contractile P2 receptors in endothelium-denuded human cerebral and omental arteries. The isometric tension of isolated vessel segments was recorded in vitro. P2 receptor mRNA expression was examined by RT-PCR.

Results

In human cerebral arteries, the selective P2Y₆ receptor agonist, UDPβS was the most potent of all the agonists tested (pEC₅₀ = 6.8 ± 0.7). The agonist potency; UDPβS > αβ-MeATP > UTPγS > ATPγS > ADPβS = 0, indicated the presence of contractile P2X₁ P2Y₂, P2Y₄ and P2Y₆, but not P2Y₁ receptors, in human cerebral arteries. In human omental arteries, UDPβS was inactive. The agonist potency; αβ-MeATP > ATPγS = UTPγS > ADPβS = UDPβS = 0, indicated the presence of contractile P2X₁, and P2Y₂ receptors, but not P2Y₁ or P2Y₆ receptors, in human omental arteries. RT-PCR analysis of endothelium-denuded human cerebral and omental arteries demonstrated P2X₁, P2Y₁, P2Y₂ and P2Y₆ receptor mRNA expression. There were no bands for the P2Y₄ receptor mRNA in the omental arteries, while barely detectable in the cerebral arteries.

Conclusions

P2Y₆ receptors play a prominent role in mediating contraction of human cerebral arteries. Conversely, no such effect can be observed in human omental arteries and previous results confirm the absence of P2Y₆ receptors in human coronary arteries. The P2Y₆ receptor might be a suitable target for the treatment of cerebral vasospasm.     

Attitudes about prescribing take-home naloxone to injection drug users for the management of heroin overdose: a survey of street-recruited injectors in the San Francisco Bay Area

Naloxone, an injectable opiate antagonist, can immediately reverse an opiate overdose and prevent overdose death. We sought to determine injection drug users’ (IDUs) attitudes about being prescribed take-home naloxone. During November 1999 to February 2000, we surveyed 82 street-recruited IDUs from the San Francisco Bay Area of California who had experienced one or more heroin overdose events. We used a questiomaire that included structured and open-ended questions. Most respondents (89%) had witnessed an overdose, and 90% reported initially attempting lay remedies in an effort to help companions survive. Only 51% reported soliciting emergency assistance (calling 911) for the last witnessed overdose, with most hesitating due to fear of police involvement. Of IDUs surveyed, 87% were strongly in favor of participating in an overdose management training program to receive take-home naloxone and training in resuscitation techniques. Nevertheless, respontdents expressed a variety of concerning attitudes. If provided naloxone, 35% predicted that they might feel comfortable using greater amounts of heroin, 62% might be less inclined to call 911 for an overdose, 30% might leave an overdose victim after naloxone resuscitation, and 46% might not be able to dissuade the victim from using heroin again to alleviate with drawal symptoms induced by naloxone. Prescribing take-home naloxone to IDUs with training in its use and in resuscitation techniques may represent a life-saving, peer-based adjunct to accessing emergency services. Nevertheless, strategies for overcoming potential risks associated with the use of take-home naloxone would need to be emphasized in an overdose management training program.     

Trends in human immunodeficiency virus seroincidence among street-recruited injection drug users in San Francisco, 1987-1998

This paper reports trends in human immunodeficiency virus (HIV) incidence among street-recruited injection drug users (IDUs) in San Francisco, California, from 1987 through 1998, estimated using a sensitive/less sensitive enzyme immunoassay testing strategy. IDUs were enrolled in 23 semiannual cross-sections from three community sites. For identification of recent infections, less sensitive enzyme immunoassay testing was performed on stored specimens that had previously tested positive for HIV antibodies. Annualized incidence rates were calculated and logistic regression models were fitted for assessment of risk factors for recent HIV infection. Among 8,065 susceptible IDUs, 34 had recent infections, for an incidence rate of 1.2% (95% confidence interval: 0.7, 2.0) per person-year. This rate declined from 2.7% in 1987/1988 to approximately 1% per person-year between 1989 and 1998. Two IDU subpopulations were at highest risk for infection: persons under age 30 years (2.8% per person-year) and men who had sex with men (3.0% per person-year). Participants who reported prior HIV test-result counseling were less likely than others to become infected (adjusted odds ratio = 0.43, 95% confidence interval: 0.21, 0.87). Sensitive/less sensitive enzyme immunoassay testing is an effective tool for assessing HIV incidence. HIV incidence among street-recruited IDUs in San Francisco appears to have remained stable and moderate since the late 1980s.     

Penicillin-induced lysis in related species of oral streptococci

Treatment of 10 strains representing 5 species of related oral streptococci with penicillin G resulted in measurable levels of cellular lysis. This lysis was dependent on penicillin concentration and cell density. At similar penicillin concentrations and cell densities, the 10 strains demonstrated appreciable differences in their lytic responses. Lysis values for Streptococcus mutans (GS-5 and Ingbritt) and Streptococcus rattus (BHT and FA-1) were greater than those for Streptococcus sobrinus (01 and B13), Streptococcus cricetus (HS6 and AHT), and Streptococcus ferus (8S1 and HD3).